PRELIMINARY TESTS ON POSSIBLE NEW STABILIZERS FOR NITROCELLULOSES

It was assumed that any practical stabilizer for nitrocellulose would have to meet the following requirements: (a) absorb nitrogen dioxide at least as avidly as the accepted stabilizer, sym-diethyldiphenylurea (Centralite); (b) cause destruction of nitrocellulose in the Bergmann–Junk heat test no greater than that caused by the accepted stabilizer, diphenylamine; (c) be no less compatible than diphenylamine with nitrocellulose; and (d) melt no higher than 80 °C., have low volatility and low solubility in water. These requirements were met by N,N′-diethyl-N,N′-di-(3-methoxy-4-ethoxybenzyl) -urea, N,N′-diethyl-N,N′-di-(3,4-dimethoxybenzyl)-succinamide, di-(3,4-dimethoxystyryl)-ketone, and perhaps by veratric aldehyde. The criteria, however, were quite inadequate to assess in a positive way any practical value of the above substances as stabilizers. A study of substances structurally related to those already mentioned revealed no correlation between avidity for nitrogen dioxide and efficiency in improving th...